Salmo g - One thing to consider, for you especially having an older motor, is the power loss from wear is so gradual that one doesn't recognize it. I can only imagine how many pounds of suspended sediment alone has passed through my pump. The real killer is driving the boat on the trailer. Ya know... a guy has to look cool on the river; as for myself, I will be doing a lot more hand cranking.
This topic really interested me, to the point that I pulled all my college fluid power books from the attic. The readings were a good refresher to confirm what I though was happening. I am really suprised that the manufacturers aren't doing these improvements on new pumps. They are just giving away power.
Yes, all of the operations can be accomplished w/ files, hand grinders, pedistal grinders...... I would bet that it would impove the performance but how much I don't know.
You could ask Titanium Cranium if he saw much improvement. I beleive that he did some work on his grates with a grinder of some sort.
A rough estimate to have the parts machined - starting at $150 and that would be real cheap. If you look in your local yellow pages you will find machine shops, mores specifically Job Shops. My shop would charge about $500.
When you call around to the smaller shops, remember people like cash.
I am willing to do the work on others pumps. I am all for bartering. Maybe, trade for a fishing trip for my girlfriend and I. I must say that I am definately not looking to make a fast buck.
Good luck,
LT